Bearing metal



Jan. 5 1926. 1,568,224-

J. KARAFIAT BEARING METAL Filed Feb. 1, 1924 -l2zu1ata Patented Jul. s, 1926.

" UNITED 'sTATEs v 1,568,224 PATENT oFFlc JOSE! KABAIIA'I', OI SCHWECEAT, NEAR VIENNA, AUSTRIA.

BEARING METAL.

Appllcaflon fled February 1, 1924. Serial No. 690,099.

To all whom it may concern:

:Be it known that I, JosEr KARAFIAT, a

I citizen of the Republic of Austria residhigher proportion of tin.

- line with its extensions reaching Alloys of said ternary system, showing various com ositions, either with or without other additions, are frequently used in practice as bearing metals. Indications as to their qualities and behaviour in practice are scarce and somewhat contradictory. Theoretical research and investigation of the constitution of these ternary alloys has led to the statements given on a triangular diagram by Loebe, (Metallurgie, vol..8, page 7). Furthermore Heyn and Bauer (Verhandlungen des Vereins zur Beforderung des Gewerbefleisses 1914, supplement) have made exhaustive studies and tests in order to obtain reliable data as to their physical properties (fusionand settingtemperature) as well as to their structure. in connection with their strength. But a.

rule for manufacturing good bearing metals by systematically substituting cheaper alloys for the expensive alloys contalnrng a high proportion of tin did not derive from said scientific research.

In the diagram-shown on the accompanying drawing, which diagram represents the composition of the said ternary alloys as usuall on an equilateral triangular system, a fielc marked III is to be seen, by which alloys of well determined compositions are graphically defined. Th1S state field III is bordered by the lines E C, (Ii- E, and by the irregular line E,E' WhlCh last to the sides of the diagram also represents t e boundary, at which the separation of bimetallic eutectic mixtures takes place. i

The present invention consists of const tuting a new bearing metal by the add1- tion ofmetals ca able of forming solid solutions with tin an lead (excepting thallium) to main alloys of said ternary system of such composition, as had hitherto never been combined therewith,viz with the main alloys tin-antimony-lead of the state field bordered within the said wellknown triangular diagram by lines connecting the following corner points:10% Sn, 10% Sb, 80% 'Pb; v

55% Sn,'5% Sb, 40% Pb;-50% Sn, 50% Sb, 0% Pb.

As a result of exhaustive experiments and examinations I have found, that exactly at the boundary between the state.

fields II and III of said diagram a sudden increase of upsetting capability takes place and that this capability reaches its maximum atthe boundary between the state fields III and IV, whilst the reduction of hardness also sets in sharply at the boundary between the state fields II and III and terminates at the boundaries between III and IV. Therefrom it resulted, that alloys of the composition according state field III, which contain two eutectics, viz: (Pb-,B) and (Pb-l-a) and besides them only B-crystals, (see the work of Heyn and Bauer referred to above) are especially adapted as main substance for hearing metals, provided that they can be hardened without becoming brittle; Thereafter it has been found, that this latter effect can be attained by the addition of metals, which ,as mercury, bismuth and cadmiumare capable of forming solid. solution with tin and lead. By the addition thereof a most marked amelioration of compressive stren h and hardness takes place without any iminution of plasticity and tenacity. An exception is thallium, which, although also forming solid'solutions, appears to be unfit for the purpose of the present invention.

In practice especially the following com-' position limits are to be considered for the main substance: Tin 20% to 52%, mony 12% to 20%, lead 28% to 68%. The amount of the hardening additions is chosen between 0.1% and 3%, for which amount preferably that of the lead is to be reduced. By practical tests it has been stated, that by adding 0.1% to 3% of mercury or bismuth the Brinell hardness index of such soft allo s is increased for about 0.3% to 4% an the specific compressive strength by 25 to 150 kilogrammes per square centimeter. Cadmium, in a quantity of 0.1 to 2%, increases the hardanti- ;pressive strength by 90 to 450 kilogrammes per square centimeter, that is to say by about as" a maximum. Accordingly,

cadmium is the best means for converting the described main substances into bearing metals, as by small additions of cadmium'it is possible toimprove the hardness and resistance to compressive strain to such an extent that alloys with an average proportion of tin become equal to alloys with a high proportion of tin. 'Mixtures of bismuth and cadmium can also be used inthe sense of the. invention within the-same composition limits, for producing bearing metals. i

The addition of small quantities of copper prevents "in the well known manner, by forming grid, any segregation or liquation, and contributes slightly to an increase of hardness and of compressive strength.

E wampl es.

shows a hardness of 254 Brinelk and a compressive strength of 1,400 kilograms per square centimeter. If one per cent of lead is replacedby cadmium, the hardness will increase to 336 Brinell and the resistance to compressive strain to 1,920 kilograms per square centimeter. 1 V

2. If in the above alloy the cadmium 1s replaced by-bismuth, the hardness will'be grams.

29.5 Brineil 'andfthe resistance to compressive strain 1,600 kilograms per square centimeter. An alloy'of a similar composition in which, in place of Bismuth, mercury is used, shows a hardness of-30 .Brinell and a compressive strength of 1,640

kilograms per square centimeter.

' signature.

1. Bearing metals of the ternary system .tin-antimonylead with an addition of metals capable of forming a solid solution with tin and lead excepting thallium, the said metalsbeing added to main substance alloys of the state field III of the diagram of the said ternary system, the corner points of'which state field represent: 10% Sii,

10% Sb, 80% Pb;55% Sn, 5% S1), 40%

Pb;50% Sn, 50% sb,0 Pb.

2. Bearing metals of the ternary system sent: 10% Sn, 10% Sb, 80% Pb ;-55% Sn, 5% Sb, 40% Pb ;--50,%Sn, 50% Sb, 0% Pb.

3. A bearing metal consisting of 20-52% tin, 12-20% antimony and 28-68% lead with substitution of a partof the lead contents by metals which are capable of forming a solid solution with tin and lead, thallium, although capable of forming, a solid solution, being excepted from addition. A bearing metal consisting of 20-52% tin, 12-20% vantimony and 28-68% lead with substitution of 01-43% of the lead contents by metals which are capable of forming a solid solution with tin and lead, thallium, :although capable of forming a solid solution, being excepted. i

5. A bearing metal consisting of 20-52% tin, 12-20%. antimony, 28-68% lead, part of the lead amounting to 0.1-3% being substituted by equal quantities of cadmium. 6. A bearing metal consisting of 20-52% tin, 12-20% antimony, 28-68% lead, part of the lead amounting to 0.1-3% being substituted by equal quantities of a mixture of cadmium and bismuth.

In testimony whereof I have aflixed my JOSEF KARAFIIAT. 

